User: | Open Learning Faculty Member:
- Identify the organism or biological attribute that you plan to study.
The organism that I choose to study is the growth rates of Sunflower plants (sp. Helianthus annuus).
- Use your field journal to document observations of your organism or biological attribute along an environmental gradient. Choose at least three locations along the gradient and observe and record any changes in the distribution, abundance, or character of your object of study.
The potted sunflower plants are located on a concrete slab in an area that is approximately 20 m2. There are a total of 8 individual plant pots setup for this experiment – located adjacent to each other – with ~0.5m of space left between individual pots and setback ~2m from any adjacent vegetation and/ or structures. Note: there are 3 sunflower plants being grown in each of the 8 pots – for a total of 24 individual sunflower plants in this study – there are 12 sunflower plants in each of the 2 study groups (a low-water volume application group & a high-water volume application study group).
Refer to the attached diagram for an overview of the study area design which shows: the plant pot setup with sunflower plants nomenclature, and adjacent vegetation/ structure. Plants replicates L1 through L12 are all in the low-water volume group and plant replicates H1-H12 are all in the high-water volume group.
There have been no visual changes observed, to date, in the distribution, character or abundance of the potted sunflower plants. This is likely because the sunflower plants seeds were recently planted on May 26th and have not yet sprouted. However, there are slight differences between the plant pot locations within the study area, including – the physical location of each pot, and the vegetation and/ or structure that is located adjacent to each pot on the perimeter of the study area. My observations at the different locations within the study area, include:
- Sunflowers plants L1-L3, & H1-H3 are all located in the SE section/ quadrat of the study area. These plants are located immediately adjacent to ornamental cedar bushes and an ornamental grass lawn on the south and east perimeters of the study area.
- Sunflowers L4-L6, & H4-H6 are located in the SW study area quadrat of the study area. These plants are located immediately adjacent to ornamental pine and cedar bushes on the south and west perimeters of the study area.
- Sunflower plants L7-L9, & H7-H9 are located in the NE study area. These plants are located immediately adjacent to an ornamental grass lawn and a house on the east and north perimeters of the study area.
- Sunflowers L10-L12 & H10-12 are located in the NW study area quadrat. These plants are located immediately adjacent to a house and cedar bushes on the north and west perimeters of the study area.
- Think about underlying processes that may cause any patterns that you have observed. Postulate one hypothesis and make one formal prediction based on that hypothesis. Your hypothesis may include the environmental gradient; however, if you come up with a hypothesis that you want to pursue within one part of the gradient or one site, that is acceptable as well.
The underlining process that may cause patterns for this study is the 2 different water volume applications (low & high), these are the studies predictor variables. My hypothesis is that any observed changes in the size of the above ground portion of the sunflower plants are likely due to the water level applications. This is considered to be a manipulative experiment – as there are 2 predictor variables – while the other factors that could potentially influence the response variable are controlled therefore, this will allow me to reject or accept my hypothesis with a high degree of certainty. My prediction is that the size and density of the above ground portion of the sunflower plants will be significantly larger in the high-water volume study group, when compared to the low-water volume study group.
- Based on your hypothesis and prediction, list one potential response variable and one potential explanatory variable and whether they would be categorical or continuous. Use the experimental design tutorial to help you with this.
The potential response variable for this study are the size of the above ground portion of the sunflower plants (continuous). The potential explanatory variable are the amount of water received (low or high group) by each plant (categorical) in the study.
Sounds like you have a good start. I wouldn’t use the word ‘likely’ in your hypothesis. Remember it should include your pattern and your process. Your hypothesis reads a lot like your prediction but not as strong.
It sounds like you’re off to a great start – your prediction is clear and falsifiable, and your data appears to be very easily measurable. The only difficulty I can see at this point is how you plan to measure the density of the sunflowers, but other than that, this looks to be a solid experiment. Best of luck!